Minimally invasive surgery is a surgical approach that involves use of instruments inserted through several tiny incision openings to perform a surgery causing minimal tissue trauma.
This minimally invasive surgery relatively reduces changes in metabolism of the patient in the period of post-surgical care, so it is beneficial to rapid recovery of the patient. Therefore, using such minimally invasive surgery shortens length of a hospital stay of the patient after the surgery and allows patients to return to normal physical activities more quickly. In addition, minimally invasive surgery causes less pain and reduces scar to patients after surgery.
The most general form of the minimally invasive surgery is endoscopy. Among them, a laparoscopy that involves minimally-invasive inspection and operation inside abdominal cavity is known as the most general form of endoscopy. To operate the standard laparoscopic surgery, an abdomen of the patient is insufflated with gas, and small incisions (about ½ inch or less) are formed for use as an entrance of a tool for the laparoscopic surgery, through which a trocar is inserted. In general, laparoscopic surgical tools include a laparoscope (for observation of a surgical site) and other working tools. Here, the working tools are similar in structure to the conventional tools used for small incision surgery, except that the end effector or working end of each tool is separated from its handle by an elongated shaft. For instance, working tools may include a clamp, a grasper, scissors, a stapler, needle holder, and so forth. To perform the surgery, a user, such as a surgeon, puts the working tool into a surgical site through the trocar, and manipulates it from the outside of abdominal cavity. Then, the surgeon monitors the procedure of the surgery through a monitor that displays the image of the surgical site that is taken by the laparoscope. The endoscopic approach similar to this is broadly used in retroperitoneoscopy, pelviscopy, arthroscopy, cisternoscopy, sinuscopy, hysteroscopy, nephroscopy, cystoscopy, urethroscopy, pyeloscopy, and so on.
Although this minimally invasive surgery has a number of advantages, it has shortcomings in the difficulty of approaching the conventional minimally invasive surgical tools to a surgical site and the inconvenient or complicate manipulation of such tools because of an end effector connected to a rigid and long shaft. Particularly, since the traditional end effector has no bending portion like a joint, it is difficult to perform a dexterous handling required for surgery. These shortcomings are the main impediment to the wide expansion of minimally invasive surgery.
To overcome these shortcomings of the traditional minimally invasive surgery, recently, a robotic assisted platform called the da Vinci® surgical system has been developed by Intuitive Surgical, Inc. The robotic assisted surgical system currently being commercialized mainly uses a master-slave type robot, which is constituted by an operating console where an operator performs an operation, a robotic cart where a robot performs an operation, and an endoscopic stack being connected thereto. An endoscopic stack in the robotic surgical system has a joint that can move in a pitch direction and a yaw direction, and thus can transfer hand motions of the operator almost exactly. Also, the robotic surgical system has a function of tremor reduction or a function of motion scaling to differentiate robot motion from hand motion in terms of scale, and can secure a three dimensional vision.
However, this robotic surgical system is very expensive equipment, and moreover, it costs a tremendous amount of money to install and maintain after installation. This equipment is also bulky and very heavy (even the robotic cart alone is about 2 m tall and as heavy as 544 kg). Needless to say, it is difficult to move the equipment around, so the surgery has to be performed only in a place where the system is already installed. Besides, in case of using the robotic system, surgeons feel lack of tactile sense, as compared with using the traditional tools for laparoscopic surgery.